Resolution of an anterior-inferior cerebellar artery feeding aneurysm with the treatment of a transverse-sigmoid dural arteriovenous fistula

The authors describe a 27-year old man who developed an unruptured anterior-inferior cerebellar artery feeding aneurysm from a transverse-sigmoid dAVF and its subsequent resolution with the treatment of the dAVF. The patient, with a known history of left transverse and sigmoid sinus thrombosis, presented with pulse-synchronous tinnitus. Angiography revealed an extensive dAVF, with feeders from both the extracranial and intracranial circulations, involving the right transverse sinus, the torcula, and the left transverse/sigmoid sinuses. Multimodal endovascular and open surgical therapy was employed. Prior to a planned second-stage treatment for the left sigmoid sinus component, the dAVF improved significantly, but a small flow-related aneurysm developed on the left AICA feeding the petrous dural region in the interval. Resection of the involved sigmoid sinus resulted in resolution of the aneurysm. This is the first reported case of an unruptured feeding-artery aneurysm in an intracranial dAVF that resolved spontaneously with the treatment of the dAVF. Until more is known about its natural history, the decision on when and whether to treat an unruptured dAVF feedingartery aneurysm must be made on an individual basis.